Silicon germanium (SiGe) layers may be utilized in semiconductor devices in many applications, such as for source/drain regions, source/drain extensions, contact plugs, a base layer of a bipolar device, or the like. Typically, SiGe layers may be epitaxially grown utilizing either dichlorosilane or silane as a silicon-containing precursor along with a germanium precursor. SiGe layers grown with dichlorosilane typically result in layers having a smooth surface, but with undesirably slow deposition rates. Thus, dichlorosilane precursors undesirably limit process throughput. Alternatively, SiGe layers may be grown using silane precursors, which tend to increase the deposition rate. However, such deposited layers typically have an undesirably rough surface. SiGe layers having rough surfaces may result in poor electrical contact with adjacent layers coupled thereto. In addition, the rough surface can result in device breakdown, or poor power consumption in devices utilizing such SiGe layers.
Thus, there is a need in the art for a method of depositing a silicon germanium (SiGe) layer on a substrate with a high deposition rate and having a smooth surface and desired properties.